/// <summary>
/// Waits for a new packet from the remote client.
/// </summary>
/// <returns>The data</returns>
/// <exception cref="IOException">If anything went wrong with the I/O</exception>
public byte[] ReceivePacket()
{
try
{
// Receives the length of the packet
int len = this.ReadByte() | (this.ReadByte() << 8);
// Reserves the space to store the data
byte[] back = new byte[len];
// Waits for the data
for (int i = 0; i < len; i++)
{
back[i] = this.ReadByte();
}
// Decrypts the data
byte[] dec = SimpleSecurityUtils.DecryptAES(back, this.aesKey, this.aesIv);
// Checks if the decryption failed
if (dec == null)
{
throw new Exception("Data-decryption failed.");
}
this.log
.Debug("Checking nonce")
.Critical($"Received bytes=[{string.Join(",",dec)}}}");
// Checks if the dec has at least enough bytes for the nonce bytes
if (dec.Length < this.nonceBytes.Length)
{
throw new IOException("No nonce provided.");
}
// Check if the bytes of the nonce match
for (int i = 0; i < this.nonceBytes.Length; i++)
{
if (this.nonceBytes[i] != dec[i])
{
throw new IOException("Nonce does not match.");
}
}
this.log
.Debug("Nonce is correct.");
// Creates a copy of the packet without the nonce
byte[] finPkt = new byte[dec.Length - this.nonceBytes.Length];
// Copies the bytes of the actual packet
Array.Copy(dec, this.nonceBytes.Length, finPkt, 0, finPkt.Length);
return(finPkt);
}
catch (Exception e)
{
// Converts any exception to an i/o-exception
throw new IOException(e.Message);
}
}
/// <summary>
/// Encryptes the given data and sends it as a packet to the receiver
/// </summary>
/// <param name="data">The raw bytes that shall be send</param>
/// <exception cref="IOException">If anything went wrong with the I/O</exception>
public void SendPacket(params byte[] data)
{
try
{
// Encryptes the data using the received key
byte[] encrypted = SimpleSecurityUtils.EncryptAES(data, this.aesKey, this.aesIv);
// Checks if anything failed with the encryption
if (encrypted == null)
{
throw new Exception("Encryption failed");
}
// Sends the length of the packet
this.stream.WriteByte((byte)encrypted.Length);
this.stream.WriteByte((byte)(encrypted.Length >> 8));
// Sends the actual encrypted data
this.stream.Write(encrypted, 0, encrypted.Length);
this.stream.Flush();
}
catch (Exception e)
{
// Converts any exception to an i/o-exception
throw new IOException(e.Message);
}
}
/// <summary>
/// Saves the config file encrypted using the passed key
/// </summary>
/// <param name="filePath">The path to the file where to save the configuration</param>
/// <param name="key">The key for encrypting the file</param>
/// <exception cref="ConfigException">Something went wrong while encryption (Unknown)</exception>
/// <exception cref="Exception">All exception that can be passed on by File.WriteAllBytes called with the filePath</exception>
public void SaveConfig(string filePath, string key)
{
// Generates the object that will be saved as the config file
JObject json = new JObject()
{
["port"] = this.Port,
["host"] = this.Host,
["rsa"] = SimpleSecurityUtils.SaveRSAToJson(this.PrivateKey)
};
// Generates the actual key and iv from the previous plain text key
byte[] aesKey = SimpleSecurityUtils.HashSHA256(Encoding.UTF8.GetBytes(key));
byte[] aesIv = SimpleSecurityUtils.HashMD5(Encoding.UTF8.GetBytes(key));
// Encryptes the config-json object
byte[] encData = SimpleSecurityUtils.EncryptAES(Encoding.UTF8.GetBytes(json.ToString()), aesKey, aesIv);
// Checks if the encryption failed
if (encData == null)
{
// Unknown exception
throw new ConfigException();
}
// Writes all data to the file
File.WriteAllBytes(filePath, encData);
}
public ConfigWindow(Config cfg, string password)
{
InitializeComponent();
this.cfg = cfg;
this.password = password;
// Sets the values
this.FieldPort.Text = cfg.Port.ToString();
this.FieldHost.Text = cfg.Host;
this.FieldRSA.Text = SimpleSecurityUtils.SaveRSAToJson(cfg.PrivateKey).ToString(Formatting.None);
// Disables the save button
this.buttonSave.IsEnabled = false;
}
private void OnButtonSaveClicked(object _, RoutedEventArgs _2)
{
// Checks if the port couldn't be passed
if (!int.TryParse(this.FieldPort.Text, out int port))
{
this.ShowError(Lang.config_save_port);
return;
}
this.cfg.Port = port;
try
{
// Tries to load the private key
this.cfg.PrivateKey = SimpleSecurityUtils.LoadRSAFromJson(JObject.Parse(this.FieldRSA.Text));
}
catch
{
this.ShowError(Lang.config_save_key);
return;
}
// Sets the host
this.cfg.Host = this.FieldHost.Text;
try
{
// Tries to save the config
this.cfg.SaveConfig(PLCA.CONFIG_PATH, this.password);
// Updates the main config
PLCA.LOADED_CONFIG = this.cfg;
// Closes the window
this.Close();
}
catch (Exception ex)
{
// Shows the error
this.ShowError(Lang.config_save_unknown, ex.Message);
}
}
/// <summary>
/// Loads the given config-file, decryptes it using the passed key and loads it as a config object
/// </summary>
/// <param name="filePath">The path to the configuration file.</param>
/// <param name="key">The key to decrypt those bytes</param>
/// <returns>The fully loaded config</returns>
/// <exception cref="ConfigInvalidKeyException">If the given key couldn't decrypt the config</exception>
/// <exception cref="ConfigCurruptedException">If the config seems to be currupted</exception>
/// <exception cref="Exception">All exception that can be passed by File.ReadAllBytes using the filepath.</exception>
public static Config LoadConfig(string filePath, string key)
{
// Reads the content of the passed config file
byte[] rawData = File.ReadAllBytes(filePath);
// Generates the actual key and iv from the previous plain text key
byte[] aesKey = SimpleSecurityUtils.HashSHA256(Encoding.UTF8.GetBytes(key));
byte[] aesIv = SimpleSecurityUtils.HashMD5(Encoding.UTF8.GetBytes(key));
// Tries to decrypt the config
byte[] decrypted = SimpleSecurityUtils.DecryptAES(rawData, aesKey, aesIv);
// Checks if the decryption failed
if (decrypted == null)
{
throw new ConfigInvalidKeyException();
}
try
{
// The config that will be created
Config cfg = new Config();
// Tries to parse the config from json
JObject json = JObject.Parse(Encoding.UTF8.GetString(decrypted));
// Gets all values
cfg.Port = (int)json["port"];
cfg.Host = (string)json["host"] ?? string.Empty;
cfg.PrivateKey = SimpleSecurityUtils.LoadRSAFromJson((JObject)json["rsa"]);
// Returns the fully loaded config
return(cfg);
}
catch
{
throw new ConfigCurruptedException(Encoding.UTF8.GetString(decrypted));
}
}
